On 7/25/2012 10:54 AM, jtpr wrote:
4" PVC to do this as it is a whole lot easier, accessible, and cheaper.
But what about static? Is it really that unsafe? Can it be grounded?
There is no evidence whatever that any small diameter dust collection
system has had an explosion or fire sparked by static discharge in plastic.
shock on occasion like the olden days of wool carpets and dry
You can attempt to minimize that by wrapping w/ wire and grounding but
since the material is nonconductive it's of marginal benefit.
The biggest pita w/ it is twofold --
1) The fittings for 4" dust collection aren't the same size as Sch 40
fittings so you have to adapt everything, and
2) It does and will collect from static charge.
But, there are thousands of applications and I've used drain/waste PVC
w/ the molded-in fittings for the main laterals here as it's
lighter/cheaper and the 10-ft joints are convenient in small shop areas.
I didn't bother to glue joints, they fit well enough to not leak
significantly and can rearrange if desired/needed.
BTW, be sure you use sweeps and larger radius fittings rather than
ordinary tight elbows for less pressure drop and fewer hangups. Also
keep the amount of flex hose to the bare minimum possible--it's the
biggest sucker-upper of airflow you can have other than a block gate.
OBTW -- on the 30-ga HVAC stuff--I've not tried it on a 2 hp collector
but it will all depend on what pressure drop your fan will pull. At
worst buy a section, hook it up to the inlet directly and do a block
test and see if you can collapse it or not.